A portable terminal of hybrid system architecture is a Personal Computer (PC) in which at least one further system is embedded into a conventional PC having only one system. Different systems can function cooperatively to achieve their respective advantages. Currently, a typical portable terminal of hybrid system architecture has a master system (e.g., x86 system) and a slave system (e.g., ARM system) integrated therein. The master system and the slave system can share their devices. In a notebook computer as an example, its slave system can function independently as a tablet computer and its master system can function independently as a host of a portable notebook computer. The user of the notebook computer can either separate these systems or connect them as an integrated system. When the user selects to use them as an integrated system, the slave system may provide the master system with an additional 3G network support, or they can be connected for synchronization of data information.
During the research on power management of the conventional portable terminal of hybrid system architecture, the inventors have recognized that the Dynamic Power Management (DPM) technique can be adopted in order to save power and increase battery lifetime of the portable terminal. Depending on the variation of the operational load of the system, the DPM technique can selectively configure system resources into a low power consumption mode by lowering or turning off the voltage or frequency of at least one circuit module when it is idle, such that the power consumption of the system can be reduced. However, this power-saving technique is designed for the standalone system architecture. That is, when applied to a portable terminal of hybrid system architecture, the above technique can only save the power consumption of the master or slave system when it is operating independently, but cannot achieve power-saving when both systems are operating cooperatively.